Blower damper mounting



y 1958 w. A. AUTRY ETAL I 2,834,535

BLOWER DAMPER MOUNTING Filed March 8, 1954 Jzz/gzzor;

'Zford A Qu 2 Poer ZflQrren Ede/250 2,83%,535 Patented May 13, 1958 BLOWER DAMPER MOUNTING Wilford A. Autry, Fort Worth, Tex., and Robert Warren Eichorn, Marshalltown, Iowa, assignors to Lennon Industries, Inc.

Application March 8, 1954, Serial No. 414,580 1 Claim. (Cl. 230-114) The present invention relates to an improved variable discharge fan or blower which may be driven at constant speed and yet has an adjustable rate of air delivery.

In the application of blowers or fans to forced air domestic heat and cooling systems it is desirable to provide some means to adjust the rate of. air delivery to the needs of the user. Excessive air delivery gives rise to drafts, noise and other undesirable effects. Insufficient air delivery prevents achieving adequate heating or cool ing and, in addition, gives rise to undesirable temperature differences within the system and the space heated and cooled.

Various means have been used to adjust the rate of air flow in heating and cooling systems. One method is to use a variable speed drive motor or a variable ratio mechanical drive connection between the motor and the blower or fan. These methods present difficulties of expense, space requirements, and inability to achieve continuous adjustment of air flow as distinguished from selecting one of several specific rates of air delivery.

In the case of systems which can accommodate dampers of one kind or another, these, too, have been used to adjust the rate of air flow. However, in the case of units discharging air directly into a room the space necessary for a damper is not usually available. In addition, dampers accent and make more noticeable the noise of the air passing through the system so that-while the air flow can be adjusted to the flow required for physical comfort-the sound level may be increased or at least made more objectionable. Also in the case of direct discharge systems the use of dampers-even if room is available-confines the air stream and thus gives rise to drafts which are only slightly less objectionable than with r the unobstructed air flow from the fan or blower.

In the apparatus of the present invention, the output of a fan or blower having a volute casing is controlled by a damper located well within the casing. The adjusting mechanism is thus located entirely within the confines of the blower or fan. In this apparatus, it has been found that the troublesome noises usually incident to the use of dampers are not developed. Additionally, the air flow is distributed rather uniformly over the area of the air outlet at all adjustments so that the velocity 'of air flow is reduced uniformly over the delivery outlet with the attendant reduction in discomfort from drafts and the absence of any tendency to create small intense air streams as the total delivery rate is reduced.

It is, therefore, a general object of the present invention to provide an improved fan or blower having a continuously adjustable rate of air delivery.

Another object of the invention is to provide an improved means for mounting the damper within the blower housing.

Still another object of the present invention is to provide an improved fan or blower having an adjustable rate of air delivery and in which the air is distributed uniformly over the entire area of the outlet passage irrespective of the air delivery adjustment.

Another object of the present invention is to provide an improved fan or blower having an adjustable rate of delivery and in which annoying sounds are minimized.

Further, it is an object of the present invention to provide an improved fan or blower of simple, inexpensive and eificient construction and yet in which the rate of air delivery is uniformly adjustable without the use of parts external to the unit.

The novel features which we believe to be characteristic of our invention are set forth with particularity in the appended claim. Our invention, itself, however, both as to its organization and method of operation together with further objects and advantages thereof will best be understood by reference to the following description taken in connection with the accompanying drawings in which:

Figure 1 is a side elevational View with parts in crosssection showing a fan or blower constructed in accordance with the present invention;

Figure 2 is a view through axis 2-2, Figure 1;

Figure 3 is a fragmentary enlarged view through axis 3-3, Figure l; and

Figure 4 is an enlarged fragmentary view through axis 44, Figure 3.

Referring now to Figure 1, there is shown generally at 16' a centrifugal blower or fan having a plurality of The shaft 12 extends axially of the rotor 10 to be driven directly by an electric at 14, Figure 2. seen in Figure 1.

The rotor 10 is surrounded by volute casing indicated generally at 16. This casing consists of end plates 16a, each of which has an arcuate inturned central air directing flange 16b which directs the air inwardly of the rotor blades 10a. These openings receive the air in axially directed movement, as shown by arrows in Figure 2. The air, thus entering into the impeller or rotor blades Illa, the blades 10a as well as a direct radial component of motion by the fan action of the blades, so that the air tends to flow spirally outwardly of the rotor, as shown by the arrows of Figures 1 and 2.

The volute casing 16 is further defined by an arcuate panel which extends between the two end plates 16a and is welded or otherwise afiixed thereto. It will be noted that the end plates 16a are in volute form at their outer peripheries. In other words, as the outer periphery of these plates is traced from about the 4 oclock position, as seen in Figure 1, to the 12 oclock position the radial distance between the shaft 12 and the periphery of the plate gradually increases.

As discussed above, the air discharged from the rotor 10 has both a circumferential and a radial component of motion. Thus the air tends to spiral. The passage defined between casing 16 is likewise of spiral conformation and defines an ever-increasing cross-section in the circumferential direction to receive the increased quantities of air flow as the passage is traced in the circum ferential direction from the narrow 4 oc1ock position to the large 12 oclock position as seen in Figure l. v

The plate 160 has a fiat tangential portion 16d which coacts with the vertical plate 16:: to form an outlet passage indicated generally at 17. Air taken into the interior of the rotor 11 is discharged through this passage, as indicated by the arrows of Figure l.

The quantity of air discharged from the fan or blower is controlled by the damper indicated generally at 18.

motor indicated. diagrammatically Rotations are in clockwise direction as is given a circumferential motion by the rotation of i The damper has an axially-extending oifset 19, best shown in Figure 4, spaced from the upper edge thereof. The damperis rockably carried by the shafts 20 which, as shown in Figure 2, supports the damper in position extending laterally between the two end plates 1611. Each shaft 20 has an axial slot in the end thereof into which the opposed margins of the offset 19 fits, as shown in Figure 4. The shafts are each held on the end plates 16a by a suitable rubber grommet 22 and are held against shifting movement by their headed end portions 20a. The damper 18 is held in each shaft by frictional pressure or other suitable means. A stifiener 18a extends laterally across the damper to prevent undue flexure of the same.

The position of the damper is controlled by the link 24 which is pivoted to the crank 26 afiixed to the damper. This link is loosely held in a suitable slot in the depending bracket 28, Figure l, and has a bent-over ear 24a adapted for connection to suitable knob means (not shown) as desired so that the damper 18 can be pulled from the position of the solid lines Figure 1-where the damper 18 is vertically oriented and minimizes the air flow-to the position shown by the dotted lines of that figure where the damper is opened and has minimum tendency to obstruct air flow.

It will be noted that the damper 18 is located well within the confines of the volute casing 16. Moreover, the damper does not obstruct all air flow from the impeller 10 to the outlet 17. Rather, there is an open air passage of substantial extent even when the damper is in the fully closed position, this passage being indicated at A.

When the damper 18 is in the fully opened position, it will be noted that there is no substantial obstruction to the outward flow of air.

The apparatus above described provides a uniformly variable quantity of air discharge through the outlet passage 17. The minimum value occurs when the damper 18 has the vertical position shown in Figure 1. At this time, however, the air issuing from portion A of the rotor 10 has an ample opportunity to difiuse and distribute itself uniformly over the outlet passage 17. Hence, the discharged air as measured externally of the unit has a rather uniform velocity covering the entire outlet area 17. Thus, the damper acts to reduce the velocity of all the air flow through the passage 17 uni- .1

formly and not merely its average value. From the standpoint of the user of the unit, therefore, the air stream which issues covers the same area at all damper adjustments and only varies in velocity.

It has been further found that with the structure described above, the noise incident to air flow in the unit is not objectionable, irrespective of the damper position. This is believed to be due to the fact that the damper does not form a restricted neck through which all the air must flow. Ratherbeing well within the volute casing-the air issuing from the unit with the damper closed is primarily air through the area A, Figure 1, and not air which passes around the damper 18. In any event, the unit has proven quiet and not subject to the annoying noises that frequently attend the use of dampers to control air flow.

It will be observed that the unit above described may be used in heating and cooling devices which discharge directly into the space heated or cooled. Since the control mechanism is disposed wholly within the volute casing, there is no need for additional equipment. Indeed, the damper control link 24 renders itself particularly well to a direct connection to an operating handle located externally of the unit.

While we have shown and described a specific embodiment of the present invention, it will of course, be understood that various modifications and alternative constructions may be made without departing from the true spirit and scope thereof. We, therefore, intend by the appended claims to cover all modifications and alternative constructions falling within their true spirit and scope.

What we claim is:

In a variable discharge blower having a rotor, a volute casing surroundingthe rotor comprising a pair of opposed end plates and an arcuate panel extending between said end plates defining a discharge passage, and a damper disposed within said discharge passage having one edge adjacent said panel, said damper extending laterally across the discharge passage and having an axially extending offset near said edge, mounting means for said damper comprising openings in said opposed end plates, a rubber grommet lining each opening having a flange in contact with the outside margin surrounding said opening and having a second flange in contact with the inside margin surrounding said opening, and a stubby shaft extending through each grommet into said discharge passage having a head engaging said one flange and an axial split in its inner end, the opposite margins of said ofiset being disposed in said axial split and bearing against said other flange, whereby said damper is pivotally mounted in insulating relation to said discharge passage.

References Cited in the file of this atent UNITED STATES PATENTS 

